Commit 3b722da6 authored by Stefan Wahren's avatar Stefan Wahren Committed by Wolfram Sang
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i2c: bcm2835: Store pointer to bus clock 



The commit bebff81f ("i2c: bcm2835: Model Divider in CCF") introduced
a NULL pointer dereference on driver unload. It seems that we can't fetch
the bus clock via devm_clk_get in bcm2835_i2c_remove. As an alternative
approach store a pointer to the bus clock in the private driver structure.

Fixes: bebff81f ("i2c: bcm2835: Model Divider in CCF")
Signed-off-by: default avatarStefan Wahren <wahrenst@gmx.net>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 42052d96

drivers/i2c/busses/i2c-bcm2835.c

+8 −9
Original line number Diff line number Diff line
@@ -58,6 +58,7 @@ struct bcm2835_i2c_dev { 
	struct i2c_adapter adapter;

	struct completion completion;

	struct i2c_msg *curr_msg;

	struct clk *bus_clk;

	int num_msgs;

	u32 msg_err;

	u8 *msg_buf;
@@ -404,7 +405,6 @@ static int bcm2835_i2c_probe(struct platform_device *pdev) 
	struct resource *mem, *irq;

	int ret;

	struct i2c_adapter *adap;

	struct clk *bus_clk;

	struct clk *mclk;

	u32 bus_clk_rate;
@@ -427,11 +427,11 @@ static int bcm2835_i2c_probe(struct platform_device *pdev) 
		return PTR_ERR(mclk);

	}



	bus_clk = bcm2835_i2c_register_div(&pdev->dev, mclk, i2c_dev);

	i2c_dev->bus_clk = bcm2835_i2c_register_div(&pdev->dev, mclk, i2c_dev);



	if (IS_ERR(bus_clk)) {

	if (IS_ERR(i2c_dev->bus_clk)) {

		dev_err(&pdev->dev, "Could not register clock\n");

		return PTR_ERR(bus_clk);

		return PTR_ERR(i2c_dev->bus_clk);

	}



	ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
@@ -442,13 +442,13 @@ static int bcm2835_i2c_probe(struct platform_device *pdev) 
		bus_clk_rate = 100000;

	}



	ret = clk_set_rate_exclusive(bus_clk, bus_clk_rate);

	ret = clk_set_rate_exclusive(i2c_dev->bus_clk, bus_clk_rate);

	if (ret < 0) {

		dev_err(&pdev->dev, "Could not set clock frequency\n");

		return ret;

	}



	ret = clk_prepare_enable(bus_clk);

	ret = clk_prepare_enable(i2c_dev->bus_clk);

	if (ret) {

		dev_err(&pdev->dev, "Couldn't prepare clock");

		return ret;
@@ -491,10 +491,9 @@ static int bcm2835_i2c_probe(struct platform_device *pdev) 
static int bcm2835_i2c_remove(struct platform_device *pdev)

{

	struct bcm2835_i2c_dev *i2c_dev = platform_get_drvdata(pdev);

	struct clk *bus_clk = devm_clk_get(i2c_dev->dev, "div");



	clk_rate_exclusive_put(bus_clk);

	clk_disable_unprepare(bus_clk);

	clk_rate_exclusive_put(i2c_dev->bus_clk);

	clk_disable_unprepare(i2c_dev->bus_clk);



	free_irq(i2c_dev->irq, i2c_dev);

	i2c_del_adapter(&i2c_dev->adapter);

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